Automatic transmission test stands are generally known. Typical of such test stands is the test stand taught in, for example, U.S. Pat. No. 4,732,036 Weeder. Weeder teaches a test stand wherein the headstock, which receives the transmission thereon while the transmission is being tested, can move transverse to the tailstock shafts, as well as being able to move vertically. The prime mover internal combustion engine also can move transversely as well as vertically, but on supports separate from the headstock supports.
U.S. Pat. No. 4,356,724 Ayoub et al teaches using an electric motor as the prime mover, as does U.S. Pat. No. 5,142,903 Mizushina et al. Ayoub et al show the electric motor fixedly secured to a support remote from the headstock support. Mizushina et al do not show the mounting support for the electric motor. Neither reference teaches any electronic apparatus for conditioning the electricity supplied to the electric motor.
In all the references known to the inventor, only flywheel-type inertia devices are taught as load devices, for applying a load to the engine during the test procedure.
No reference known to the inventor provides a single test stand for testing automatic transmissions wherein the headstock is mounted to the main frame with sufficient freedom of movement to mount and test all of (1) rear wheel drive transmissions, (2) transverse mounted front wheel drive transmissions, and (3) longitudinally mounted front wheel drive transmissions.
No reference teaches or suggests mounting an electric motor as the prime mover to the same support that mounts the headstock which receives the transmission. Neither does any reference teach using electric brakes.
It is an object of this invention to provide an improved transmission tester, and methods of use, wherein an electric motor is provided as the prime mover, fixedly secured for adjusting movement relative to a braking unit, in combination with the headstock and corresponding transmission secured to the headstock.
It is another object to provide a transmission tester, and methods of use, wherein an electric motor is provided as the prime mover, and is adapted to temporarily suspend acceleration when the transmission shifts gears.
It is a further object to provide a transmission tester wherein the headstock can pivot about a vertical axis, to thereby receive a longitudinally mounted transaxle, as well as to receive transversely mounted transaxles and rear wheel drive transmissions.
It is another object to provide a load device, for providing an active load simulating the deadweight load of a range of vehicle weights.
It is a more specific object to provide a load device adapted to apply a mechanical resistance load within a range of available torque values, including selecting one or more torque values as part of testing each transmission.
It is a still more specific object to provide an eddy current brake as an active load device, for applying resistance torque to the transmission while the transmission is being tested.